This invention relates to an improvement in the adjustment of an image exposure apparatus which makes exposure for photosensitive materials using a light emitted from a plurality of light emitting elements of plural colors.
There are image exposure apparatus which are equipped with an array light source composed of a plurality of light emitting elements for each of the recording colors and make exposure for photosensitive materials (such as photographic papers).
FIG. 17 is an illustration showing how exposure is carried out in a conventional image exposure apparatus of this kind. In this apparatus, in order to make exposure for a photographic paper 11, there are provided array light sources 1, 2, and 3 having about the same width as the photographic paper 11. In the example shown here, vacuum fluorescent tubes are used for the array light sources, and each of the array light sources 1, 2, and 3 is composed of two lines of a zigzag arrangement of 20 elements. Besides, in the case where LED""s are used for an array light source, the elements have a straight line structure.
In the above-described example, the array light sources 1, 2, and 3 are ones emitting lights corresponding to the respective recording colors of R, G, and B. Further, exposures for R, G, and B are made at the same positions of the photographic paper 11 by actuating each of the array light sources 1, 2, and 3 at timings shifted in accordance with the transport speed while the photographic paper 11 is being transported in the direction of the arrow mark in the drawing.
Moreover, it is desirable that there is a light source which can emit at a time line-shaped light dots having a desired density as shown in FIG. 18. For example, in the case where the line-shaped light dots having a density of 100 dots per a line is necessary, 100 elements for R, 100 elements for G, and 100 elements for R are necessary, which means that it is necessary to make a light source having total 300 elements arranged in a line. That is, for a light source to obtain a light emission of 100 dots per line, 300 dots per line is the desired density.
However, because there is a limit in the size of the light emitting element, it is difficult to arrange all the elements in a line. For this reason, as described in the above, the exposure is made in a structure such that array light sources are provided for the respective colors to make exposures sequentially.
Generally speaking, because a bundle of rays from an array light source is divergent, it is necessary to form an image of the light source on the photographic paper, or to make the light source become in close contact with the photographic paper.
Because the light sources are in close contact with the paper in this way, or because the brightness of the image decreases if the image forming surface is let away in the case where the image of the light source is formed on the photographic paper, it has been necessary as an actual matter that the exposure is carried out with an arrangement of array light sources 1, 2, and 3 shifted from one another as shown in FIG. 17.
In the case where the exposure is made with such an arrangement of the array light sources for the respective recording colors shifted from one another, it is necessary to shift the timing of the driving signals supplied to the respective array light sources 1, 2, and 3 in accordance with the transport speed of the photographic paper. For this reason, there is a problem that the structure of the driving circuit and the timing control are made complex.
Further, if a fluctuation of transport speed occurs after an exposure for a certain recording color before the next exposure for another color with respect to the same pixels is carried out, it produces a color deviation. Accordingly, in order to prevent the color deviation, it has been necessary to control strictly the transport speed of the photographic paper 11.
Further, because a minute movement of the photographic paper 11 in the direction perpendicular to the transporting plane becomes a cause to produce a color deviation owing to the variation of the size of the image of the pixel on the photographic paper, it is necessary to keep the position of the transporting plane precisely. However, a mechanism for keeping the transporting plane precisely as described in the above is necessary for each of the above-described three light sources, and it is also necessary that the mechanism covers the range extending over the all light sources (the range A shown in FIG. 19). Moreover, it has been necessary also a mechanism suppressing the movement of the paper in the direction perpendicular to the transporting in the transporting plane during an interval until the next exposure for another color with respect to the same pixels is carried out.
That is, as shown in FIG. 19, in the cases where recording is made with an arrangement of array light sources 1, 2, and 3 for the respective recording colors, there has been a situation that an exposure without a color deviation and unevenness of color is difficult.
For the reasons described in the above, it is also thinkable to carry out exposure for the photographic paper 11 after combining line-shaped emitted lights beforehand; however, for such a case, nothing has been considered with respect to the points how the line-shaped emitted lights are combined, and how the state of the deviation and the focusing of the combined line-shaped lights are detected and adjusted.
This invention has been done in view of the above-described technical problems, and it is an object of the invention to provide an image exposure apparatus which makes the structure of the driving circuit and the timing control easy, produces no color deviation even if a fluctuation of transport speed occurs, and is easy to be adjusted.
That is, this invention for solving the above-described problems is such one as described in the following structures.
(1) An image exposing apparatus for exposing an image onto a light sensitive material, comprises:
a plurality of light beam emitting element arrays, each light beam emitting element array emitting aligned-light beams which are aligned in at least a single line;
light mixing means for mixing a plurality of aligned-light beams emitted from the plurality of light beam emitting element arrays and for emitting mixed-aligned-light beams which are aligned in the same line;
light receiving means located so as to receive the mixed-aligned-light beams at a position where the light sensitive material is exposed; and
adjusting means for adjusting a position of each of the plurality of light beam emitting element arrays based on a light receiving result by the light receiving means.
(2) In the image exposing apparatus of (1), the position adjusting means conducts an exposing position adjustment for adjusting an exposing position of each of the plurality of aligned-light beams emitted from the plurality of light beam emitting element arrays and a focusing position of each of the plurality of aligned-light beams at the position where the light sensitive material is exposed.
(3) In the image exposing apparatus of (1), the light receiving means receives light beams in order to conduct a control for light emission intensity of the plurality of light beam emitting element arrays and in order to conduct an exposing position adjustment and a focusing position adjustment.
(4) In the image exposing apparatus of (1), the light receiving means is detachably provided to the image exposing apparatus.
(5) In the image exposing apparatus of (1), wherein the light receiving means comprises CCD (charge-coupled device).
(6) The image exposing apparatus of (1), the adjusting means corrects a light amount for each element of the plurality of light beam emitting element arrays based Qn the light receiving result by the light receiving means.
(7) In the image exposing apparatus of (1), the light receiving means comprises light receiving elements and an optical system to transmit light beams emitted on an image forming surface of the plurality of light beam emitting element arrays and to focus the transmitted light beams on an image forming surface of the light receiving elements.
(8) In the image exposing apparatus of (5), the CCD is a line CCD.
(9) In the image exposing apparatus of (8), the light receiving means has a structure that the line CCD is inclined so as to cover an arrangement width of zigzag-arranged light beam emitting element array and a warping width of a light beam emitting element array.
(10) In the image exposing apparatus of (7), wherein the optical system comprises a scanning mirror to scan the image forming surface of the image forming surface of the plurality of light beam emitting element arrays.
(11) In the image exposing apparatus of (7), the light receiving means further comprises color filters to adjust a sensitivity for respective colors.
(12) In the image exposing apparatus of (7), the light receiving means detects positional deviations along a sub-scanning direction perpendicular to the light beam emitting element array and automatically produces control parameters.
(13) In the image exposing apparatus of (7), the light receiving means detects focusing errors as positional deviations in an optical axis.
(14) In the image exposing apparatus of (7), wherein the light receiving means detects an inclination and a warp in the light beam emitting element array.
Further, the above object may be attained by the following preferable structures.
This invention is an image exposure apparatus which makes image exposure for photosensitive materials using a plurality of light emitting element arrays, comprising light mixing means for mixing lights emitted from said plurality of light emitting element arrays to form mixed line-shaped emerging lights on one and the same line, light receiving means for receiving the line-shaped emerging lights obtained through mixing by said light mixing means at the position where said photosensitive materials are subjected to an exposure, and adjusting means for adjusting the positions of said light emitting element arrays on the basis of the result of receiving the light by said light receiving means.
Besides, it is desirable that the aforesaid adjusting means makes the adjustment of the exposure positions of the line-shaped emitted lights from the aforesaid plurality of light emitting element arrays, and the focus adjustment at the position of exposure of the aforesaid photosensitive materials to the aforesaid mixed line-shaped emerging lights.
In this invention; bundles of rays from a plurality of array light sources are mixed by a light mixing means and made to emerge from it, to form line-shaped emerging lights composed of a plurality of mixed bundles of rays. Further, through making the adjustment of the positions of the light emitting element arrays by the adjusting means, adjustment to correct positions and focus adjustment are made possible.
Accordingly, because the bundles of rays from the respective array light sources are put together to make exposure for one line, it is actualized an image exposure apparatus which has a simple structure of the driving circuit and an easy timing control, produces no color deviation even if a fluctuation of transport speed occurs, and is easy to be adjusted.
Moreover, it is possible for the light receiving means to receive a light for both of the purposes, that is, the control of the light emission intensity of the light emitting element arrays and the adjustment of the exposure positions and the focuses. In other words, it is possible to use the light receiving means for controlling the light emission intensity of the light emitting element arrays in the adjustment of the exposure positions and the focuses.
Further, there may take place positional dispersion in light emitting position in a light beam emitting element array in which this dispersion can not be adjusted by the adjustment for the light beam emitting element array and adjustment dispersion in adjustment result caused by adjustment. However, with the above structure, it is possible to add means for automatically correcting the positional dispersion and the adjustment dispersion on the basis of the detection result of the light receiving means.